Crankshafts are mechanical components that perform a conversion between a rotational motion and a reciprocating motion. The crankshaft is attached to a piston assembly for conversion of the rotational motion to the reciprocating motion. Typically, the linear displacement produced by the piston assembly in the engine cylinder is constant once running and cannot be varied during operation. Conventional crankshafts lack the ability to vary the linear displacement of the piston assembly during operation. A crankshaft, which is capable of varying the linear displacement of the piston assembly during operation, is required. Additionally, in conventional crankshafts, if a force or a substance prevents the piston from reaching the top or bottom dead center, the crank stops or it damages one of the parts. The crankshaft is not flexible and stops operating when the crank meets resistance. A crankshaft, which is flexible and functions even when the crank meets resistance, is required.
Traditionally, in multi-cylinder engines that use conventional crankshafts, the motion of piston of a cylinder cannot be changed relative to other cylinders. For instance, the motion of each piston of the multi-cylinder engine cannot be decreased separately. A crankshaft, which permits the motion of each piston of the multi-cylinder engine to be varied separately, is required. Additionally, over the years, various mechanisms for converting rotational motion to reciprocating linear motion have been developed. Some of these mechanisms have the ability to change the amount of linear motion. Each of the mechanisms devised have various disadvantages, which limit the use of them. For instance, to perform a reciprocating motion with different lengths, hydraulic cylinders along with hydraulic pump are used. However, this method uses high energy, is highly complex, and involves high cost of construction. As another solution, pneumatic cylinders along with a pump perform a reciprocating motion with different lengths, but with lower accuracy.
The use of the pump and the pneumatic cylinder has several disadvantages, for example, consumes high energy, is highly complex, has a high cost of construction, has low accuracy, and a slow reaction. In addition, another popular method is the use of the electric linear actuator system with an electric generator. This method also suffers similar drawbacks, for example, high-energy consumption, high complexity, and high cost of construction. A crankshaft, which provides varying linear displacements without high-energy consumption and has a low cost of construction, is required.
Hence, there is a long felt but unresolved need for a crankshaft, which is capable of varying the linear displacement of the piston assembly during operation. Moreover, there is a need for a crankshaft, which is flexible and works well even when the crank meets resistance. Furthermore, there is a need for a crankshaft, which provides varying linear displacements without high-energy consumption and has a low cost of construction.